Flotation concentrator



v Feb; 19, I929.

. w JOHNSQN FLOTATION CONCENTRATOR 2 Sheets-Sheet l Fil ed April 30.1927 M 4 finial 71.5011

an on W14 Patented Feb. 19, 1929.

UNITED STATES- AXEL W. JOHNSON, OF NEDERLAND, COLORADO.

I FLO'IATION CONGENTRATOR.

Application filed April 30, 1927. Serial No. 188,010.

I This invention relates to flotation concentrating machines wherein allconcentration is secured by the use of a froth. The general object ofthis invention is to provide a con-j centrator of this character whichrequires no power to operate, but in which the frothing of the liquid inthe frothing cell is secured by discharging the liquid into the frothingcell from a height and through a vertical feed column.

A further object is to provide a machine of this character which isadapted for all floatable ores and which will handle ores as coarse asfifteen mesh without any liability of choking.

A further object in this connection is to provide a mechanism which hasno small pipes to choke, no mechanical agitators, and has practically noparts to wear out.

A further object is to provide a mechanism of this character including afrothing cell, a vertical feed column discharging into the frothingcell, a skimmer for carrying off the froth with its floated particlesofore, means for carrying off the sands and water from the frothingcell, and means operated by the current of sands and water for operatingthe skimmer.

My invention is illustrated in the accompanying drawings, wherein Fig. 1is a plan view of my device constructed in accordance with my invention;

Fig. 2 is a longitudinal sectional view on the line 2-2 of Figure 1;

Fig. 3 is an end elevation of the device;

Figure 4 is a transverse section on the line d4c of Figure 2; I

Figure 5 is a diagrammatic sectional View illustrating the operation ofthe device;

Figure 6 is a similar view of- Figure 5 in plan.

Referring to the'se'drawings' 10 designates the frothing cell whichisshown as approximately rectangular in plan and which has an upwardlyand forwardly inclined front wall 11, a downwardly and forwardlyinclined froth discharge board 12, and a vertical rear wall 13.Extending downward into the rear end of the frothing cell is the feedcolumn 14 which extends upward, to any desired height, and is preferablyrectangular in section and has a discharge opening at its lower end, thelower end of the pipe being out 01f at a downward and rearwardinclination so that the advance of the discharge feed column is adownwardly and rearwardly inclined wall 15 which extends nearly to thebottom of the frothing cell, but is formed with a rectangular aperture16 coinciding with the discharge .mouth of the feed column. At one endofthe frothing cell, there isdisposed a sand launder 16 into which theoverflow launders or troughs 17 discharge. These troughs 17 are disposedagainst the end wall 18 of the frothing cell, this end wall being cutaway as at 19 upon its upper edge face. A sand discharge opening 20extends through the end wall 18 and discharges into the launder 16 andthe effective area of this opening is controlled by a damper 21 havingthe form of a lever pivoted upon the end wall 18 and shiftable to coveror uncover the opening 20. The handle of this damper operates againstthe inside face of the wall 18 and inward of the wall 18 is a bafli'eboard 22, the upper edge of which is 1 trough 2 1 which extends entirelybeneath the machine and receives sand and water from the launder 16 andfrom the sand wheel housing 23. The bottom of this troughis inclineddownward in one direction so as to carry olf the water and sanddischarged from the launder 16 and from the sand wheel housing.

Disposed within the sand wheel housing is the water wheel 25 mountedupon the shaft 26 which extends through one wall of the sand wheelhousing and carries upon it the belt wheel 27. Separating the sand wheelhousing 23' from the frothing cell is the end wall 28 of'the frothingcell which is cut away upon its upper edge as at 29 and which is formedwith the opening 30'leading into the sand wheel housing at a pointslightly below the axis of the water wheel 25. The eifective size ofthis opening is controlled by the damper 31 having a handle or leverextending upward to the top of the machine so that t may be readilyoperated. Exterior to the wall 28 there are provided the overflow chutesor troughs 32 which discharge any water pass ing over the upper edge ofthe wall 28 into the sand wheel housing. Inward of the wall 28, there isdisposed the baffle board 33 ofthe same character as the bafl le board22. The

wall 15 abuts at its ends against these bafile boards and. below thebafile boards abuts at its ends against the end walls of the frothingcell.

Mounted in bearings upon the end walls of the frothing cell is a shaft34 carrying upon it the skimmer 35 which may be formed of thin metal orany other suitable material. to provide reversely curved wings. Theskimmershaft is driven by the pulley or band wheel 36, driven by a bandfrom the pulley 27, which in turn is driven by the water wheel.

In the operation of this mechanism, the pulp with the frothing agent isdischarged into the column 14 and descends vertically into the frothingcell with such violence as to cause the proper frothing of the agent.The froth or bubbles so produced support the particles of ore in themanner well known and the deflecting wall 15 acts to cause a whirlingand rolling agitation of the pulp such as is produced by a mechanicalrevolving agitator and this froth is immediately removed by the skimmer35 and discharged over the discharge board 12. The sand and otherforeign matter which falls to the bottom of the cell is dischargedthrough the openings 20 and 30 into the sand launder 16 and into thesand Wheel housing 23. By closing one of these openings and entirelyopening the other, the sand and water may be discharged in eitherdirection desired, thus for instance all of the sand and water may bedischarged into the sand wheel housing to operate the water wheel or if.this would cause too rapid an operation of the water wheel, andtherefore of the skimmer, a portion of the sand and water may bedischarged into the launder 16. The re cesses 19 and 29 act to hold thepulp and water at a constant level within the frothing cell, this levelbeing below the top of the frothing cell. The bafiie boards 22 and 33'act to prevent the froth from escaping through these overflow recesses19 and 29. The pulp is fed through the vertical feed column and the fallof pulpthrough this column forces a sufficient amount of air into thefrothing cell and into the pulp and frothing agent so as to cause suchagitation as to produce a mineral bearing froth without the necessity ofusing any mechanically operating agitators. The sand in the pulp sinksto the bottom of the cell and around pocket or bowl is formed in thissand by the downward discharge of the pulp through the feed column. Thisbowl spreads or deflects upwardly rising currents of the pulp so as tosecure a uniform and proper agitation of the pulp.

It will be seen that this machine requires no power, has no parts towear out, no small pipes to choke up, and no mechanical agitators. Itmakes a particularly clean product, cleaner than the products of powerdriven machines and requires no attention. The proportion of concentratesecured by this machine is relatively high. The economy of theconstruction enables a number of these machines to be installed throughwhich the pulp can be run until the values are all saved, and thisinstallation and operation of the machine will be less than the cost ofany machine requiring mechanical power to operate it. By eliminating themechanical agitators, etc., I secure not only economy in cost, buteconomy of operation in that I eliminate the use of a motor, engine orother mechanical device, andfurther there is no necessity of continuedor constant supervision of the machinery. I have found in actualpractice that the-provision of the sand bowl at the bottom. of thefrothing cell and through the elfect'of the downwardly dischargingcolumn of materials acts to thoroughly agitate and mix the pulp and oilsin the frothing cell and this agitation will be more thoroughlyperformed than by any form of mechanical agitation known to me. Thereare no small pipes for the injection of airas the feed pipe takes insufficient air for proper aeration, the force of the falling pulp andwater drawing down and heating the air into the pulp and water in thefrothing cell. The level of the water in the frothing cell is maintainedat all times no matter how great the influx 0f the pulp and water maybe. This does away with a constant supervision.

In Figure 5, I show a vertical sectional view of the cell whichillustrates the manner in which the sand bowl is formed and the mannerin which the froth is directed by the deflecting board or wall towardsthe skimmer. As shown in Figure 6, diagrammatically the main bowl A isformed immediately beneath the discharge pipe and beneath the upwardlyextending wall 15. This bowl A projects outward to a point in frontof avertical plane touching the edge of the wall 15. Forward of this mainbowl A two subsidiary bowls B are formed separated from each other by adividing wall C. These bowls B are scoured out by the passage of sandand water and other like material toward the sand discharge apertureswhereby the water and sand Attention is particularly called to thefunction of the deflecting board 15, as disclosed in Figure 5. As thepulp flows down the relatively long tubular member 14 and en.- trainsair with it, the pulp is discharged into the sand bowl and this sandbowl acts to defleet the flow to an upward current which strikes theunder face of the deflecting board 15, this board extending transverselyentirely across the cell and extending on each side of the column 14 tothe rear of the cell. The deflecting board 15 acts to cause a slightdownward current of the pulp and part of this downward current of pulpenters again into the sand bowl and the other part, seeking thedischarge outlet, comes in contact with the upward current of the pulpand is again drawn upwardly, thus giving a circular movement ofagitation'to the pulp. Thus the deflecting board 15 acts to obtain awhirling agitation of the pulp such as ordinarily secured by amechanical revolving agitator. The deflecting board 15 does not act as acrowding board to crowd the froth forward and over the discharge lip.The deflecting board 15 is too far back from the discharge lip to giveany such action and this is shown by the fact that in actualpractice'the froth appears a few inches from the upper margin of thedeflecting board and remains in this position in a state of rest untilthe skimmer draws the froth forward and over the dis charge lip.

It is to be particularly noted that the feed pipe 14 has anapproximately uniform cross sectional area for its entire length, or atany rate, for a length sufficient to secure a high velocity for the pulpmoving downward through this feed pipe so that the pulp is deliveredinto the cell with a high velocity and without any possible impediment.The pulp carries with it entrained air and the velocity of the pulp asit discharges into the frothing cell agitates the pulp below the levelof liquid in the frothing cell so as to form a froth capable of liftingup with it the particles of mineral matter. One of the features of thisinvention is the provision of a feed pipe which is relatively high andwhich is of uniform cross sectional areathrough its length so that therecan'be no impediment to the downward discharge of the pulp.

With regard to the formation of the sand bowl A, the agitation by thisbowl is more effective than if there were nothing there to change andspread the current of the descending pulp. To thoroughly agitate thematerial in the pulp, it is necessary that some sort of abaflle bepresent to violently spread the uprising current and this must be donebe fore the descending pulp loses any of its velocity. The said bowlacts to do all this much better than if an artificial bowl or bafflewere used, for the reason that the sand bowl is naturally formed andbuilds up according to the velocity and amount of feed. Thus the sandbowl is naturally formed and is, in a sense, automatically taken care ofat all times.

I claim 1. A froth flotation concentrator including a frothing cell, avertically disposed feed column having a substantially uniform crosssectional area from top to bottom extending vertically down into thecell and discharging below the level of the liquid contents of the cell,the feed column being open only at its upper end for the inlet of pulpand entrained air, and an upwardly and forwardly inclined deflectingwall intersecting the lower extremity of the feed column and extendingto the ends of the frothing cell and on each side of the column to therear of the frothing cell.

2. A flotation concentrator including a frothing cell, a verticallydisposed feed column having its lower end terminating within the celland below the level of liquid therein and adjacent the rear wall of thecell, the lower end of the feed column being forwardly and upwardlyinclined, and a deflecting board through which the lower end of the feedcolumn passes, the deflecting board ex tending upwardly and forwardly tothe top of the cell at the same inclination as the lower end of the feedcolumn and extending transversely to the ends of the cell.

3. A flotation concentrator including a frothing cell, a tall, straight,vertically disposed feed column unbroken throughout its length andhaving its lower end terminating within the cell and below the level ofliquid therein, the lower end of the feed column be ing forwardly andupwardly inclined, and an upwardly and forwardly inclined deflectingboard intersecting the lower end of the feed column extending laterallyto the ends of the cell, and means disposed in spaced relation to andadjacent the forward wall of the cell whereby the froth may be drawnover the upper edge of the forward wall.

4. A froth flotation concentrator including a frothing cell, means fordischarging pulp and entrained air into the frothing cell, a rotatableskimmer mounted at the front of the cell, a water wheel casing disposedat one end of the cell and communicating therewith near the bottom, a.water wheel therein operated by the discharge from the cell, a manuallyoperable valve for controlling theflow of sand and water into saidcasing, and means for driving the skimmer from said water wheel.

In testimony whereof I hereunto affix my signature.

AXEL W. JOHNSON.

